At the present time the dye treatment of human hair occurs most often in a consumer's home, or at a hair salon.
For home hair dye treatment, the customer will select a dye from a wide assortment of colors. For example, one manufacturer may sell a line of home dye products in about fifty to one hundred colors. That range of colors often results in hair color that is unsatisfactory to the consumer, as she is not familiar with the dye color, based on her hair, required to obtain the final color she desires. A consumer may have a mental picture of a certain dark shade of blonde, but the final color of her hair may be lighter or darker or more or less yellow than the color she envisioned. A hair dye's effect on hair depends on many factors, including the color of the user's hair and dye fastness (ability to retain color).
The colors, to a non-professional, may appear almost the same. For example, Clairol's type X63 is medium reddish brown, X62 is medium brown and X64 is medium ash brown. L'Oreal's 24 is "cocoa medium brown", 26 is "Redwood-Auburne" and 30 is "Chestnut Reddish Brown".
The average consumer often does not have the training or experience to accurately predict the final color of her hair when she uses a home hair dye kit. In addition, due to the large number of color dyes, a store may not have an inventory of all colors. A store may stock almost a full range (about one hundred) of one company's colors; but have a more limited inventory of another company's colors. A store carrying just two lines may have over 200 different dyes; which poses problems in maintaining so many colors in stock.
Consequently, many consumers use the services of a professional hair colorist at a hair salon. A trained and experienced hair colorist has experience dyeing hundreds of heads of hair and can reasonably accurately predict the final color of a hair dye treatment. The consumer may select the color she desires from a color chart having a broad range of many colors.
Hair dye manufacturers presently make various lines of hair dye colors. A typical line may consist of over one hundred different bottles, with each bottle containing a different color hair dye. In some respects, such a system is expensive, cumbersome and wasteful. It requires that the salon maintain a large and complete inventory of bottles of dye. The cost of a complete inventory of one manufacturer's line is about fifteen thousand dollars. Generally, the dyes are subject to degradation by oxygen. So when a bottle is opened, partly used and saved, its contents may be degraded by oxygen in a few weeks. In addition, the hair colorist may lack the experience, with a particular type of hair, to properly select the hair dye color bottle, or bottles, to obtain the desired result.
To change hair color through use of oxidative dyes, it is known to use specific dye intermediates that are dissolved in an alkali media (pH 7.5-10.5) and carried by various types of gel and creme emulsions, or liquid solutions. These hair colorants are generally combined with a developer solution containing an oxidizer (usually hydrogen peroxide) at a pH of 2-4. Mixing ratios generally vary from 1:1 to 1:2 (ratio of tint to developer). The strength of the mixture depends upon the amount of natural pigmentation one desires to remove from the hair, i.e, "lightening strength". When mixed, the mixture maintains a pH similar to that of the tint or dye media. This higher pH is required for the hydrogen peroxide to oxidize the dye intermediates, causing them to couple inside the hair structure and form colored molecules which, due to their molecular size, are trapped within the structure of the hair, thus the terminology "permanent haircolor". The oxidizer will also remove some of the natural pigmentation in the hair, causing a lightening or blonding effect. The extent of lightening is regulated by the pH and peroxide strength of the tint/developer mixture. Generally products containing weak alkalizers, i.e., aminomethylpropanol or bicarbonates, and having a pH of 7-9, will produce little or no noticeable lightening of the natural hair pigmentation. Such products are termed "no-lift" or "deposit only" haircolorants and they are generally used to blend gray hair or to enhance natural color. Products that contain stronger alkalizers, such as ammonia or ethanolamine and have a pH of 9.0-10.5, will deposit color and lighten the natural pigmentation, allowing for the possibility of producing blonde shades. In order to achieve all of these desired effects, as mentioned previously, hair salons often purchase several haircolor lines with shade inventories frequently exceeding one hundred or more.
The paint industry faced a similar problem. It was common practice years ago for a paint manufacturer to produce a line of 6-10 paint colors. A consumer could only buy that limited number of colored paints. If he wanted a different color he had to mix in additional color pigment, or mix cans of color paint. That system required a large inventory of paints for the various colors, especially considering the different sizes (pints, quarts, gallons) and the different surfaces (flat, gloss, semi-gloss). Presently, one may select a desired paint color from a broad range of colors and that paint color is mixed at a store, generally by adding color to a neutral base.
That type of color mixing system has not been applied on a commercial scale either in stores selling home hair dye kits or in hair salons. One reason may be that presently available hair dyes are generally degraded by oxygen. The paint mixers used in stores are not suitable to dispense hair dyes as they permit oxygen to reach the product. Another reason is that the amount of hair dye that is used for each treatment is relatively small so that if color additives are to be mixed they must be added in exact amounts. The type of exact liquid measurement required is at the one-tenth of a milliliter (ml) level. Devices for measuring at that level of accuracy are found in chemical laboratories, not in hair salons.
U.S. Pat. No. 3,208,639 discloses a machine for metering and dispensing fluids, such as dyes, for dyeing or tinting women's hair. The fluid conducting portions not filled with fluid are filled with an inert gas above atmospheric pressure. In contrast, the present invention does not use insert gas. In U.S. Pat. No. 3,208,639 different predetermined colors and shades of dye solution may be blended by combining basic dye color solutions and one dilutent. The liquid reservoirs are rigid containers having a sealing puncturable cover material, such as foil.
U.S. Pat. No. 4,871,262 discloses a cosmetic dispensing system for mixing skin cosmetics, such as facial creams and makeup foundations. Liquid additives are stored in bottles and are pumped, by peristaltic pumps, to be mixed with a cosmetic cream base in a jar.
U.S. Pat. No. 5,366,117 shows a condiment dispenser for dispensing a group of condiments, such as mustard and ketchup, through a common nozzle. A propellant gas, such as carbon dioxide, drives a dual chamber fluid pump. The system is closed against oxygen contamination and the condiments are held in collapsible bags.